The number of oxygen atoms present in 20 4 g of Al2O3are equal to the number of (Al=27) (A) O - Chemistry - Some Basic Concepts of Chemistry

Question

The number of oxygen atoms present in 20 4 g of
Al​2O3are equal to the number of
(Al=27) (A) O atoms in 3 6 g of H2O (B) O atoms in 5 4 g
of H2O (C) H atoms in 5 4 g of H2O (D) H
atoms in 10 8 g of H2O

Geetha · Accepted Answer

The number of moles and atoms for each substance is calculated
Number of moles = Given massMolar mass20
 4 g of Al2O3 =20 4102 = 0
2 moleNumber of atoms of oxygen =3 × 0
2 × 6 022 ×1023 =3
6 × 1023 atomsThis is equivalent to H atoms in 5
4 g of water
Number of moles = Given massMolar mass5
 4 g of H2O=5 418 = 0
3 moleNumber of atoms of hydrogen=2 × 0
3 × 6 022 ×1023 =3
6 × 1023 atomsThus option C is correct

The number of oxygen atoms present in 20.4 g of Al​2O3are equal to the number of (Al=27) (A) O atoms in 3.6 g of H2O (B) O atoms in 5.4 g of H2O (C) H atoms in 5.4 g of H2O (D) H atoms in 10.8 g of H2O

The number of oxygen atoms present in 20.4 g of Al₂O₃are equal to the number of (Al=27) (A) O atoms in 3.6 g of H₂O (B) O atoms in 5.4 g of H₂O (C) H atoms in 5.4 g of H₂O (D) H atoms in 10.8 g of H₂O